The purpose of this project is to provide independent consultation to researchers within the NCI on problems related to biostatistical methodology and cancer control. Current projects include: - in collaboration with the Cancer Prevention Studies Branch, the American Association of Retired Persons (AARP) Observational Cohort Study has entered its second year; during the past year, the mailed baseline food frequency questionnaire was completed and returned by over 600,000 AARP members; potential participants in a validation/calibration substudy were selected and enrolled; two 24-hour diet recalls were obtained by telephone for the 2,000 substudy subjects; the results are currently being entered into computer form and analysis will soon begin; this project will construct a cohort of AARP members to investigate the relationship between their current dietary intake and their future incidence of cancer of the breast, colon/rectum, and prostate. - in collaboration with the Cancer Prevention Studies Branch, we completed research projects on 1) dietary folate intake and colorectal cancer and 2) the effects of dietary fat and fiber intake on androgen and estrogen levels in men. - in collaboration with the Cancer Prevention Studies Branch and the Applied Research Branch, a newly developed food frequency questionnaire (FFQ) is being evaluated; participants are currently being enrolled in a study using a daily checklist of selected foods to evaluate the food frequency accuracies of a sample of questionnaire items; the responses to an RFP for estimating the new questionnaire's measurement errors of selected nutrients and comparing its error to that of two other commonly used FFQs were evaluated, a proposal was selected for award and negotiations are currently underway; robust regression methods to convert food frequencies into nutritional intakes based on the subject's age, gender and FFQ-reported portion size are being developed and evaluated. - in consultation with the Applied Research Branch, DCPC and the Office of Cancer Communications, evaluatating the accuracy of the Cancer Information System services to the general public is continuing. - in collaboration with the Epidemiology and Biostatistics Program of the DCEG, dietary data from a case control study of lung cancer in women are currently being examined. - in consultation to the Laboratory of Chemoprevention, DCEG, we analyzed results of a study on the tumor-suppressor activity of the transforming growth factor- (TGF-beta) and the results of an experiment of the anti-prostate tumor effect of combining raloxifene with either 9-cis-retinoic acid or 4-HPR. - in collaboration with the Prevention and Control Extramural Branch, the Section provides consultation on the analysis and evaluation of the 5 A Day Program -- NCI's campaign to increase fruit and vegetable consumption. - in collaboration with the Environmental Epidemiology Branch, DCEG, gender differences in cytochrome P4501A2 are being investigated in relation to differences in dietary intake.